thin (thickness depends on wafer diameter, but is less than 1 mm), circular slice of single-crystal semiconductor material used in manufacturing of semiconductor devices and integrated circuits; depending on material wafer diameter may range from about 25 mm to 300 mm; cut from the ingot of single crystal semiconductor.

Czochralski crystal growth, CZ

process of obtaining single-crystal solids; the most common method for obtaining large diameter semiconductor wafers (e.g. 300 mm Si wafers); single crystal material is pulled out of the melt in which single-crystal seed is immersed and then slowly withdrawn; desired conductivity type and doping level is accomplished by adding dopants to the melt.

float-zone crystal growth, FZ

method used to form single crystal semiconductor substrates; alternative to CZ crystal growth process; polycrystalline material (typically in the form of a circular rod) is converted into single-crystal by zone heating (zone melting) starting at the plane where single crystal seed is contacting polycrystalline material; used to make Si wafers; results in very high purity (i.e. very high resistivity) single crystal Si; does not allow as large Si wafers as CZ does (200 mm and 300 mm); radial distribution of dopant in FZ wafer not as uniform as in CZ wafer; wafers used in high-end Si microelectronics are almost uniquely CZ grown.

ingot

circular in shape piece of single-crystal semiconductor material typically resulting from the Czochralski crystal growth process; ingot is shaped and then sliced, using high-precision diamond saw, into wafers used to manufacture semiconductor devices.

wafer diameter

depending on material and needs semiconductor substrates are available in the form of circular "wafers" 0.5 mm to 1 mm thick and ranging in diameter from 1 inch (25 mm) to 12 inch (300 mm).

wafer fabrication

process in which single crystal semiconductor in the form of a rod or boule in transformed by cutting, grinding, polishing, and cleaning into circular wafer (with desired diameter) used in semiconductor manufacturing.

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wafer bonding

process in which two semiconductor wafers are bonded to form a single substrate featuring specific properties; commonly applied to form SOI substrates; bonding of wafers of different materials, e.g. GaAs on Si, or SiC on Si; is of great interest.

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wafer charging

process of acquiring static electric charge by the wafer during processing; highly undesired effect that needs to be monitored and controlled.

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wafer diameter

depending on material and needs semiconductor substrates are available in the form of circular "wafers" 0.5 mm to 1 mm thick and ranging in diameter from 1 inch (25 mm) to 12 inch (300 mm).

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wafer fabrication

process in which single crystal semiconductor in the form of a rod or boule in transformed by cutting, grinding, polishing, and cleaning into circular wafer (with desired diameter) used in semiconductor manufacturing.

slicing

term refers to the process of cutting of the single-crystal semiconductor into wafers; high precision diamond blades are used.

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wafer flat

a feature machined at the perimeter of the semiconductor wafer; location and number of wafer flats contain information on the orientation of the crystal and the dopant type (n- or p-type).

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wafer reclaiming,

laping and/or etching then plishing and cleaning procedure which removes patterns and/or scratches from the surface of the processed wafer and allows it to be re-used.

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Wafer Scale Integration, WSI

an integrated circuit is not limited to a single chip, but is spread over the entire wafer; in effect, the whole wafer acts as a chip.

chip

piece of semiconductor wafer containing the entire circuit.

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wafer track

term typically refers to a track-like set up which integrates several instruments needed to processes photoresist (deposition, soft bake, exposure, developing, hard bake...)in advanced semiconductor manufacturing.

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wafer warpage

highly undesired deformation of the processed wafer due to the stress that can be introduced by aggressive thermal treatments; sometime referred to as a "potato chip effect".